Move - A Web3 Language and Runtime

The Aptos blockchain consists of validator nodes that run a consensus protocol. The consensus protocol agrees upon the ordering of transactions and their output when executed on the Move Virtual Machine (MoveVM). Each validator node translates transactions along with the current blockchain ledger state as input into the VM. The MoveVM processes this input to produce a changeset or storage delta as output. Once consensus agrees and commits to the output, it becomes publicly visible. In this guide, we will introduce you to core Move concepts and how they apply to developing on Aptos.

What is Move?

Move is a safe and secure programming language for Web3 that emphasizes scarcity and access control. Any assets in Move can be represented by or stored within resource. Scarcity is enforced by default as structs cannot be accidentally duplicated or dropped. Only structs that have explicitly been defined at the bytecode layer as copy can be duplicated and drop can be dropped, respectively.

Access control comes from both the notion of accounts and module access privileges. A module in Move may either be a library or a program that can create, store, or transfer assets. Move ensures that only public module functions may be accessed by other modules. Unless a struct has a public constructor, it can only be constructed within the module that defines it. Similarly, fields within a struct can only be accessed and mutated within its module that or via public accessors and setters. Furthermore, structs defined with key can be stored and read from global storage only within the module defines it. Structs with store can be stored within another store or key struct inside or outside the module that defines that struct.

In Move, a transaction's sender is represented by a signer, a verified owner of a specific account. The signer has the highest level of permission in Move and is the only entity capable of adding resources into an account. In addition, a module developer can require that a signer be present to access resources or modify assets stored within an account.

Comparison to other VMs

	Aptos / Move	Solana / SeaLevel	EVM	Sui / Move
Data storage	Stored at a global address or within the owner's account	Stored within the owner's account associated with a program	Stored within the account associated with a smart contract	Stored at a global address
Parallelization	Capable of inferring parallelization at runtime within Aptos	Requires specifying all data accessed	Currently serial nothing in production	Requires specifying all data accessed
Transaction safety	Sequence number	Transaction uniqueness	nonces, similar to sequence numbers	Transaction uniqueness
Type safety	Module structs and generics	Program structs	Contract types	Module structs and generics
Function calling	Static dispatch	Static dispatch	Dynamic dispatch	Static dispatch
Authenticated Storage	Yes	No	Yes	No
Object global accessibility	Yes	Not applicable	Not applicable	No, can be placed in other objects

Aptos Move features

Each deployment of the MoveVM has the ability to extend the core MoveVM with additional features via an adapter layer. Furthermore, MoveVM has a framework to support standard operations much like a computer has an operating system.

The Aptos Move adapter features include:

• Move Objects that offer an extensible programming model for globally access to heterogeneous set of resources stored at a single address on-chain.
• Cryptography primitives for building scalable, privacy-preserving dapps.
• Resource accounts that offer programmable accounts on-chain, which can be useful for DAOs (decentralized autonomous organizations), shared accounts, or building complex applications on-chain.
• Tables for storing key, value data within an account at scale.
• Parallelism via Block-STM that enables concurrent execution of transactions without any input from the user.
• Multi-agent framework that enables a single transaction to be submitted with multiple distinct signer entities.

The Aptos framework ships with many useful libraries:

• An Aptos Token Objects standard as defined in AIP-11 and AIP-22 that makes it possible to create interoperable NFTs with either lightweight smart contract development or none at all.
• A Coin standard that makes it possible to create type-safe Coins by publishing a trivial module.
• A Fungible asset standard as defined in AIP-21 to modernize the coin concept with better programmability and controls.
• A staking and delegation framework.
• A type_of service to identify at run-time the address, module, and struct name of a given type.
• A timestamp service that provides a monotonically increasing clock that maps to the actual current Unix time.

With updates frequently.

More Resources

Developers can begin their journey in Move by heading over to our Move developer page.